1. Field of the Invention
This invention relates to an improvement of roller blinds controller, more particularly to a roller blinds controller easy in locating and assembling purpose, in which a ridge portion is provided on limiting rod for secure fixing so as to achieve the purpose of easy assembling.
2. Brief Description of the Prior Art
Conventional window curtain structure, other than window blinds and horizontal draw-pull window covering, still has a roller blinds structure enabling to roll up and down in vertical direction. Ordinary roller blinds structure substantially has a controller provided at one end of a roller tube on which a rolling fabric is rolled up. Two side brackets are respectively provided at the other end of the roller tube and the head end of the controller. Meanwhile, a pulling cord, usually a bead chain, is provided on the controller, and whereby up-down of the fabric, upon pulling of the cord by users, can be controlled by the controller and the rolling fabric can be stopped at any intermediate position as desired by users.
Conventional roller blinds structures have been proposed, such as Taiwanese Patent Gazette No. 395220 entitled “A roller blind controller”, No. 428468 entitled “A spring structure adapted to roller blinds controller”, or No. 579803 entitled “Improvement of roller blinds controller structure”. Each of theses structures is substantially formed, as depicted in FIG. 4, by a limiting rod (71), a sleeve cover (72), a side cover (73), and an outer sheath (74). The limiting rod (71) has an inserting segment at one end, and an open slot (711) and an engaging protrusion (712) at the other end thereof. A bead chain sprocket (721) for meshing a bead chain (75) is fitted on the inserting segment, and one end of the bead chain sprocket (721) is connected to the sleeve cover (72) which is rotated simultaneously upon the pulling of the bead chain (75). The sleeve cover (72) has a hollowed portion (722) the two edges of which are abutted by the two ends of a torsion spring (76) fitted on the limiting rod (71). Finally, an outer sheath (74) is assembled in such a manner that the engaging protrusion (712) of the limiting rod (71) is snap-fitted on the outer sheath (74); thereby a roller blinds controller (7) is completed. In the assembly process of the above structure, when the limiting rod (71) is inserted through the side cover (73), it is only in free state without being positioned in place so that the limiting rod (71) is in a state of possibly coming off the side cover (73). Even after the subsequent fitting of the sleeve cover (72) and the torsion spring (76), all the members are in unseated messy state until the outer sheath (74) is assembled to be snap-fitted with the engaging protrusion (712) of the limiting rod (71). Thus, the assembly is inconvenient.